I could be missing some recent news, and I'm also not well informed on the topic.

But, it seeems there is a lot of misinformation circulating.

The FDA didn't BAN NMN, they are making it be classified as a medicine rather than a nutritional supplement. So, many places like Amazon removed it from being sold since the NMN producers/sellers aren't registered with the government to sell over-the-counter medication.

maybe it will be sold in the likes of aspirin(for lack of thinking up a better medicine) or something.

the issue you mention wouldnt be a concern of what countries follow the FDA regulations, ifs it a product being sold over the counter in the US, it would be subject to customs if shipped elsewhere. So it would never leave the country if it weren't allowed.

I could be missing something, but it seems there is a lot of misinformation circling here.